<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Document</title>
  <script src="lib/jquery.js"></script>
  <script>
    $(function(){
      $('button').click(function(){
        $.ajax({
          url:'http://127.0.0.1:3001/getdata2',
          success:function(res){
            console.log('请求获取数据成功.res=' + res)
          }
        })
      })
    })
    // 点击按钮,发起请求, 这时候看看浏览器的前进和后退按钮有没有反应?
  </script>
</head>
<body>
  <button>点我发送请求</button>
</body>
</html>